The invention relates to an X-ray imaging method, comprising the forming of a set of a plurality of two-dimensional X-Ray projection images of a medical or veterinary object to be examined through a scanning rotation by an X-Ray source viz à viz said object, which X-Ray images are acquired at respective predetermined time instants with respect to a functionality process produced by said object, and from said set of X-Ray projection images reconstructing by back-projection a three-dimensional volume image of said object.
Such methods have been in use for cardiac and other medical diagnostic operations. The prime problem for acquiring an appropriate 3D or 4D data set from the 2-dimensional images is the movement of items within the human or other body under consideration, which movement is sometimes substantially periodic, but not completely so. In other circumstances, the object in question, such as an intestine can be considered as moving in quite an irregular manner. Furthermore, the object may undergo secondary motion, such as caused by breathing or consciously moving. It is therefore a problem that various two-dimensional images do not refer back to an identical 3D object, which would render their applicability less good. However, for a top-quality reconstruction the number of processed two-dimensional images should be as high as possible, whilst raising the amount of available data that is in the same “phase” of the motion, as far as such phase is detectable.